“BSP thread” commonly refers to a type of thread used in pipe fittings and connectors. BSP stands for British Standard Pipe, and it is a set of technical standards for threaded pipes and pipe fittings. BSP threads come in two main types: BSPP (British Standard Pipe Parallel) and BSPT (British Standard Pipe Taper).
BSPP (British Standard Pipe Parallel): In BSPP threads, the threads are parallel to each other. The sealing is typically achieved with the help of an O-ring or a gasket. BSPP threads do not have a taper, meaning the diameter remains constant along the length of the fitting. Please see below picture of connection type.
BSPT (British Standard Pipe Taper): BSPT threads, on the other hand, have a taper, meaning the diameter of the thread increases or decreases along the length of the fitting. The sealing in BSPT threads is achieved through the taper itself. When two BSPT threads are screwed together, they form a tight seal due to the increasing diameter. Please see below picture of connection type.
These standards are widely used in plumbing and piping systems, especially in the United Kingdom and many Commonwealth countries. When working with pipes and fittings, it’s crucial to use the correct thread type to ensure a proper seal and prevent leaks.